CHANGES OF RAT MESOTHELIAL CELL PROPERTIE S IN PROCESSES OF SPONTANEOUS AND ASBESTOS-INDUCED TRANSFORMATION IN CULTURE

The processes of spontaneous and asbestos-induced transformation of ra t mesothelium were studied using cell culture. The cells became sponta neously transformed at 22-24 passages, while the asbestos-induced tran sformation of them ensued at 14-16 passage. The same changes of cell p roperties were established both in spontaneous and asbestos-induced tr ansformation: change of epidermal growth factor (EGF) response, appear ance of fibroblast-like cells instead of polygonal ones, appearance of multilayer cell growth foci and semisolid agar colonies. The asbestos -induced transformation began earlier than the spontaneous one: EGF be gan to stimulate the mesothelium proliferation instead of its inhibiti on at passage 6-7 in case of asbestos-induced transformation whereas i t takes place at spontaneous one at 9-10, fibroblast-like cells were o bserved at 10-11 instead of passage 17-18, and the ability for semi-so lid media growth appeared at passage 14-16 in place of 22-24.